The recent emergent use of monoliths as stationary phase in chromatography and other sorption technologies, i.e. replacement of packed-bed column in capillaries with monolithic materials, has resulted in significant advancement in chromatography separation and analytical sciences (Svec et. al., 2000; Colon et. al., 2000, Zou et. al., 2002). In addition to lower pressure drop, improved separation efficiency, decreased dispersion due to thermal gradients, and faster separations, monoliths are much more reproducible in performance than packed columns in capillaries. Current monolith development in the field has been limited to organic polymeric media (e.g., styrene divinylbenzene-based materials) (Svec et. al., 2000). Inorganic materials such as functionalized silica particles have been examined as packing materials inside glass capillaries (Luedtke et. al., 2000; Tanaka et. al., 2002). A few papers reported the use of sol-gel bonded silica particles as “continuous beds” in columns or as “monoliths” inside glass capillaries or tubes (Tang et. al., 1999; Tang and Lee, 2000; Ratnayake et. al., 2000).
Major techniques used or being developed for biomolecule separations (DNA sizing and sequencing) include gel electrophoresis (GE), capillary electrophoresis (CE) and capillary electrochromatography (CEC) (Pursch and Sander, 2000). The GE/CE technique separates only charged species while the CEC separates both charged and neutral species. For GE, uniform preparation and loading of gels are labor intensive. Only limited number of samples can be loaded per gel. The gel typically used in laboratory applications is polyacrylamide; however, its monomer is very toxic and the gel is fragile. To increase the maximum number of samples, the latest development in CE utilizes bundled glass capillaries, but they are still fragile and tedious to operate. Both gels and glass capillary are not suitable for large-scale separations. Fibril monoliths are needed to enable the scale-up of capillary electrophoresis and capillary electrochromatography.